https://desktop.arcgis.com/en/arcobjects/latest/net/IGPNAHierarchySettingsType.htm
IGPNAHierarchySettingsType Interface (ArcObjects .NET 10.8 SDK)
ArcGIS Developer Help IGPNAHierarchySettingsType Interface Provides access to properties/methods of the geoprocessing network analyst hierarchy settings type.
interfacesdk